Liquid fuel burner for outdoor dryer installations



y 1965 E. H. FRAENZEL LIQUID FUEL BURNER FOR OUTDOOR DRYER INSTALLATIONS Filed May a, 1963 IN VENTOR E. H. F uenzel 2 Sheets-Sheet l ATTORNEY y 0, 1965 E. H- FRAENZEL LIQUID FUEL BURNER FOR OUTDOOR DRYER INSTALLATIONS INVENTOR E.H. Frcenzel BY W ATTORNEY United States Patent Edward E. Fraenzel, 3613 Westover Drive, Danville, Va. Filed May 6, 1963, Ser. No. 27%,924 Qlairns. (6!. 158-77) The present invention relates to improvements in high capacity liquid fuel burners, and more particularly to a fuel burner of the atomizer type for use in connection with outdoor aggregate retort dryers or kilns, and other types of outdoor heating installations.

One object of the invention is to provide a unitary self contained liquid fuel burner capable of being employed in outdoor dryer installations and having a housing to protect the various burner components from the elements and severe weather conditions.

Another object is to provide a liquid fuel burner of he above mentioned type in which the housing contains all of the operating controls for the burner, as well as the electric motor, bearing assemblies and various other controls therefor.

Another object is to provide a liquid fuel burner having a unitary housing in which all of the burner elements are completely housed to exclude moisture, as well as foreign particles and which is shaped to provide upper and lower portions for housing such oil burner parts as oil valves, control motors, ignition transformers and flame safeguards.

Another object is to provide a high capacity liquid fuel burner in which the upper portion of the housing structure is rounded to form an impeller or rotary vane type air motor casing with its axis of rotation aligned with the axis of the atomizing burner cup.

Another object is to provide a high capacity liquid fuel burner which will supply sufiicient heat to dry various aggregate materials in dryers or kilns of the retort type, and which will burn on a relatively low flame for positive and automatic ignition.

Another object is to provide a high capacity liquid fuel burner which will operate on various inexpensive grades of fuel oil and will produce a long penetrating flame required for aggregate dryers with a relatively low consumption of electrical energy and horsepower.

Another object is to provide a high capacity liquid fuel burner of the atomizer type having a rotary cup to atomize the fuel, thereby requiring only a suificicnt amount of air to shape the flame and support initial combustion.

Another object is to provide a liquid fuel burner housing structure which is shaped to provide a duct internally thereof and formed by a wall portion of said casing.

Other objects and advantages of the invention will become apparent during the course of the following description of the accompanying drawings wherein:

FIGURE 1 is a front elevational view of the burner structure showing the front wall of the housing removed to illustrate the arrangement and association of the various elements.

FlGURE 2 is a side elevational view of the burner apparatus with the side plate removed to illustrate the manner in which the burner is supported in the upper end of the housing and the motor driven blower supported in the lower portion thereof.

FIGURE 3 is a fragmentary cross sectional view taken on the zigzag line 33 of FIGURE 1 looking in the direction of the arrows and illustrating the burner assembly and the manner in which the weight controlled damper is operated to maintain economical operation of the rotary burner, and

FIGURE 4 is a vertical cross sectional view taken on lines 4 of FIGURE 3 illustrating the impeller and Bidihlil Patented July 20, 1%65 lCe the manner in which the same is rotatably and antifrictionally supported.

In the drawings, and more in detail, there is shown a compact and unitary oil burner primarily intended for use in connection with outdoor installations such as dryers and kilns in which the various parts of the dryer installation are exposed to the atmosphere and are subjected to inclement weather conditions such as rain and snow, as well as foreign particles and matter. The burner structure generally comprises a rotary oil cup which is rotated solely by an air motor supplied with air at an increased velocity supplied by a blower.

As shown in FIGURE 1 there is provided a housing generally designated 5 in which is mounted a blower generally designated 6 driven by an electric motor generally designated 7. The burner assembly is mounted in the upper end of the housing 5 and is generally designated 8.

The housing d includes a pair of parallel spaced apart I beams 16 connected by suitably spaced transverse bars ii. A housing floor i2 is supported on the upper flanges of the l beams it and on the transverse spaced bars 11. The housing includes front and rear walls 13 and 14 and opposed side walls 15 connected at their upper ends by an arcuately curved portion 16. The housing may be formed of detachable side plates suitably connected to the front and rear walls 13 and 14 with one of the opposed side walls forming a portion of the air duct connecting the blower and rotary air motor.

The blower d is of the Roots-Connersville type and includes a blower casing 13 having intake and exhaust sections i and 2h. The casing 13 is provided with a pair of spaced supporting brackets 21 which are bolted or otherwise afiixed to the housing floor 12 as at 22. It has been found desirable to employ a blower of the low pressure type in which a pair of interengaging vanes mounted on parallel shafts 24 and 25 are employed. Thus, less horsepower is required in operation of the burner apparatus, and the blower can be driven by an electric motor 7 the casing of which as at 2:: has its base 2'7 afiixed to the floor 12 of the housing. The motor 26 is provided with an armature shaft 28 to which is attached the hub 29 of a V-belt pulley 3%. Similarly, one of the shafts 25 of the blower 6 is provided with the hub 31 of a V-belt pulley 32, and a V-belt 33 is trained over the pulleys to drivingly connect the armature shaft 23 to the blower shaft 25. The blower e is preferably of the type having interengaging impellers on the shafts 2d and 25 which create a circulation of air through the inlet port boss 19, and discharges the same through the outlet or discharge boss 2%.

Secured to the arcuately curved wall portion lb of the housing 5 is a plate 36 having an arcuately curved edge which is welded to the curved portion of the wall 15 as at 3?. The plate 36 forms one wall of an air motor generally designated 3, while the other radial wall is formed by a flange 3% integrated with a flame shaping cylinder 39 (FIG. 3) The outer end of the cylinder 39 is of frusto-conical shape and projects beyond the front wall 13 a considerable distance and substantially the major portion of its length. The annular flange 38 on the cylindrical member 39 is secured to the arcuately curved wall 16 by means of a suitable threaded fastener, or if desired a series of machine screws may be employed to securely anchor the cylinder 39 in place. The plate 36 and flange 33 are arranged in spaced parallel relation to form therebetween an air motor chamber which is enclosed for a portion of its circumference by means of an annular wall 42 extending around the annular tlange 38. The upper portion of the circular wall 42 is interrupted to provide a tangential air inlet and extending along said interrupted portion there is provided a :3 division plate 43 (FIG. 3). Thus, the interrupted portion of the annular casing 42 provides a tangential air inlet 44 to the air motor casing formed by the transverse plate 36, and the annular flange 38 of the cylinder 39.

Suitably afiixed to the plate 36 is an anti-friction bearing housing 45 having an annular flange 47 intermediate its ends. The bearing housing 45 is inserted in an opening 49 in the plate 36 so that the flange 47 abuts the marginal edge of the opening so that the housing 45 can be securely held in place by a series of circumferentially spaced threaded fasteners 50 such as machine screws or the like which extend through openings in the flanges 47 and have their inner ends received in correspondingly threaded openings in the plate 36.

Rotatably mounted in the bearing housing 45 is a rotary shaft 52 having internal raceways 53, and said internal raceways 53 are supported by anti-friction bearings 54 mounted in external raceways 56 secured in enlarged portions 58 of the bearing housing 45. The cylindrical bearing housing 45 is open at both ends and is closed at its outer end by a cover plate 60 held in place by circumferentially spaced threaded fastener elements 62. A central opening 64 is provided to accommodate the outer threaded end of a fuel pipe 66 which extends through the tubular shaft 52 and is provided on its opposite end with a T-shaped spray nozzle having radially extending ports .(not shown) to discharge the liquid fuel to the burner.

Mounted on the rotary shaft 52 is the hub 70 of the motor impeller which includes a hub-shaped extension 71 terminating in a radial'wall 72 which is of a diameter to fit within the circular wall 42 of the housing formed between the plate 36 and radial flange 38. The cup-shaped portion 71 of the hub 70 forms a chamber 73 for receiving the projecting end of the cylindrical bearing housing 45 and also positions the radial wall 72 of the impeller in closely spaced relation from the plate 36. The hub 70 is secured to the rotary shaft 52 by means of a suitable set screw 75 to rigidly secure the same in place.

The impeller (FIG. 4) includes a series of circumferentially spaced radial vanes 77 having angle portions 78 which are secured in place by suitable fastener elements 79 such as machine screws or the like, and the impeller occupies the annular chamber 81 formed between the wall 36, annular flange 38 and circumferential wall 42. Thus, air under pressure entering the tangntial opening 44 will impinge against the blades 77 and rotate the same in a clockwise direction looking in the direction of FIGURE 1. If desired, the angular portions 78 of the blades can be spot welded to the radial impeller wall 72 or can be secured thereto in any approved manner.

The exhaust air from the air motor is discharged centrally through an annular space 82 between the cylinder 39 and the cup-shaped portion 71 of the hub 70, and hence, the discharged air travels in the direction toward the front wall 13.

Also mounted on the rotary shaft 52. adjacent its free outer end is the hub 90 of a burner cup 92, and said hub is secured in place on the shaft 52 by means of a set screw or the like 93. The burner cup 92 is arranged concentrically with respect to the cylinder 39 and in spaced relation thereto to form an annular air space 94 between the outer peripheral wall of the burner cup 92 and the cylinder 39. Secured to the housing front wall 13 and extending around an opening 95 is a cone-shaped member 96 having a radial flange 97 which is secured to the housing wall 13 by a series of circumferentially spaced threaded fasteners 98 (FIG. 3). The top wall 16 is provided with an arcuately curved projection 99 for receiving the threaded fasteners 98 adjacent the upper curved portion of the radial flange 97. The conical member 96 is spaced from the flame. direction cylinder .39 and forms an annular chamber 100 concentric with the burner cup 92 for the discharge of air from the blower source to shape the flame beyond the burner cup 92.

Mounted on the internal surface of the frusto-conical portion 40 of the cylinder 39 is a series of circumferentially spaced blades 101, and said blades may be welded or otherwise secured in place and are angled to extend in a direction opposite to the direction of cup rotation. Thus, with the impeller including the radial wall 72 and blades 77 rotating in a clockwise direction (FIG. 1) the blades 101 will extend longitudinally of the cup 92 and cylinder 39 extending in an angular counterclockwise direction looking at FIGURE 1.

The anti-friction bearings 54 permit free rotation of the tubular shaft 52 and the bearing assemblies are provided with seals 101 to exclude foreign matter therefrom. The threaded outer end of the liquid fuel pipe 66 is connected to a suitable fuel supply pipe extending through the rear housing wall 14 in any approved manner and is fixed against rotation. Thus, the spray head 67 remains in a fixed position and the spray orifices (not shown) feed liquid fuel to the rotary cup 92.

Air is supplied to the burner assembly from the blower 6 through a duct system which includes a supply pipe 102 of channel section having side walls 103 connected by a wall 104. One of the upstanding vertical walls 15 forms the remaining wall for the duct 102 and the side walls 103 i of the channel shaped ducts are welded to the wall 15 on the inner surface thereof from the wall as at 104 to a point extending along the upper curved wall 16 and terminating as at 105. Extending from the wall 104 to the blower 6 is an elbow portion 107 which is provided with a flange 108 connected to the discharge boss 20 of the blower by suitable threaded fasteners 109 which extend through the flange 108 and are received in correspondingly threaded. openings in the face of the discharge boss 20. The elbow portion 107 is formed by curved extensions of the side walls 103 and an extension of the connecting wall 102. A curved plate 110 extends from the wall 104 to the flange 108 to complete the duct structure.

The upper portions of the side walls 103 are similarly curved as at 111 and the wall 104 curves in a direction tangential to the air motor 8 as at 112.

The curved wall portion 112 terminates at the inlet portion 44 of the air motor casing and the curved wall portion 111 merges with the plate 35 to close the air space about the inlet opening 44. Thus, it will be seen, that the duct 102 is formed by walls 103, 104, 13 and 15, and that the duct is mounted in the corner of the housing 5 between the front wall 13 and one of the side walls 15. At the point where the lower portion of the duct 102 enters the air blower 6 the portion 107 extends at a compound angle and is connected to the boss 20 by suitable threaded fasteners (FIGURE 2).

A. circulatory duct of square section has one end provided with a flange 121 which is bolted to the intake boss 19 and has its flange 121 secured to said boss by suitable threaded fasteners or machine screws 122. The other end of the duct 120 is connected to the wall 104 of the duct 102 and is provided with a gravity biased damper plate 123 which is pivotally mounted on a shaft 124 journaled in the wall 103 of the duct and the front wall 13 of the housing. Formed in the duct 120 is an air intake opening 125 having a screen cover 126 to admit air to the intake side of the blower 6.

Pivotally mounted between the side wall 15 and the wall 104 of the duct 102 is a gravity biased damper 130 which is mounted on a shaft 131 to which is attached an arm 132. A weight 133 is secured to the arm 132 to normally urge theupper end of the damper 130 into engagment with the plate 43. Thus, the damper 130 can be set by regulating the weight 133 on the arm 132 by adjusting the set screw and locking the weight 133 in any desired preselected position.

Also journaled in the wall 103 adjacent the upper portion 111 and the front wall 13 is a shaft 134 on which is mounted a slotted sector shaped arm 135 which can be secured in place by means of a suitable thumb screw 135 extending through a slot 137 in the sector shaped arm 135. The shaft 134 is provided with a vane 133 which is movable toward and away from the impeller disc 72. to control the passage of air through the intake 44.

A suitable ignition device is adapted to be mounted adjacent the burner structure and this includes a pilot flame presented to the burner nozzle 67 to ignite the liquid fuel sprayed therefrom. The pilot ignition device (not shown) is adapted to be supplied from a suitable source of flammable gas such as bottled gas or the like.

The housing 5 has its rear Wall provided with an offset 14! having formed in the top and bottom thereof a series of louvres 141 and 142 respectively to admit air to the interior of the housing and supply air to the blower 6 through the intake opening 125.

In operation, air is supplied to the air motor under pressure by the blower 6 which passes through the duct Hi2 and is controlled by the vane 13% which can be set to any predetermined position to control the flow of air to the tubine air motor casing. The movable damper 131i) is balanced by the weight 133 to bypass air to the air motor and turbine wheel when the fuel burner is operating at low capacity. This carries air only to the top of the turbine wheel to prevent stalling of the wheel when operating at low capacity.

The vane 139 will permit excess air to pass through the annular passage between the cylinder 39 and the coneshaped heat shield 96, and when said air passes through said annular passage it is directed in a direction opposite to the direction of cup rotation by means of the vanes tilt) and thus has the propensity of shaping the flame emitted from the burner cup. During ignition of the burner when the same is operating at low capacity the air from the blower will be directed through the casing 42 and rotate the impeller '72, thus rotating the burner cup 92 at a maximum speed. If excess air is produced by the blower during its normal operation the vane 13% will move to an open position and permit a portion of the air from the blower to pass through the annular air space between the cylinder 39 and the heat shield cone 96.

It is to be understood that the form of the invention shown and described is to be taken as a preferred embodiment thereof, and that various changes in the organization of elements can be made without departing from the spirit of the invention or the scope of the subjoined claims.

What I claim is:

1. In a liquid fuel burner for outdoor dryer installations, comprising a vertical housing having a front wall provided with an opening in the upper portion thereof, an air motor casing mounted in said housing in back of said opening in the upper portion of said vertical housing, said casing providing a motor chamber, a cylindrical extension on said motor casing communicating with said chamber forming an air discharge passage therefrom, a motor shaft rotatably mounted in said chamber in said casing, a rotor on said shaft having vanes adapted to be driven by air entering the casing through an inlet opening therein, a burner cup on said motor shaft extending through the opening in said front wall and arranged concentrically with respect to said cylinder. a motor driven blower in the lower portion of said housing beneath said air motor casing having an inlet and an outlet, an electric motor drivingly connected to said blower, duct means common to at least one wall of said housing connected to said outlet and to the air intake in said motor casing, and a frustoconical member secured to said housing about the marginal edge of said opening therein and arranged concentrically with respect to said cylinder and burner cup for directing air in a convergent path to the burner cup, said motor driven blower, air motor casing and duct means being completely confined in said housing.

2. In a liquid fuel burner for outdoor dryer installations, comprising a vertical housing having front, rear and side walls connected at the upper portion by an arcuate wall portion, said front wall being provided with an opening in the upper portion thereof, an air motor casing mounted in back of said opening in the upper portion thereof having a peripheral air inlet and a central discharge opening, a rotary shaft mounted in said air motor casing, a vaned rotor mounted on said shaft, an atomizer cup secured to one end of said shaft to extend through said opening, a cylindrical extension on said motor casing arranged concentrically with respect to said cup to form an annular chamber therebetween communicating with said central discharge opening for permitting the discharge of air from the motor to pass through said annular chamber formed between said cylinder and cup, at frusto-conical ring secured to said housing and attached to the marginal edge of said opening, a motor driven blower mounted in the lower portion of said housing beneath said air motor having air inlet and discharge openings, an electric motor driving connected to said blower, duct means extending from the discharge opening of said blower to the peripheral inlet of said motor, said duct means having two Walls common to the front and side walls of said housing, the major portion of siad duct means being formed by the front wall and one of the side walls of said housing, a weight controlled valve in said duct means adapted to permit air flow through an annular space between said cylinder and frusto conical member, said blower and motor being confined in said housing.

3. In a liquid fuel burner for outdoor dryer installations, comprising a vertical housing having front, rear and side walls connected at the upper portion by an ai'cuately curved wall, said front wall being provided with an opening in the upper end thereof, an air motor casing mounted in back of said opening having a peripheral air inlet and a central discharge opening, a rotary shaft mounted in said casing, a vaned rotor mounted on said shaft, an atomizer cup secured to one end of said shaft and extending through said opening, a cylin drical extension on said casing arranged concentrically with respect to said cup for permitting the passage of air discharged from said motor, a frusto-conical ring secured to said housing and attached to the marginal edge of said opening, a motor driven blower mounted in the lower portion of said housing having air inlet and discharge openings, an electric motor drivingly connected to said lower, duct means extending from the discharge opening of said blower to a peripheral inlet in the casing of said air motor, an air return duct connected to said duct means and to the inlet opening of said blower, said return duct being provided with a screened air inlet, a gravity biased valve plate pivoted to said duct means to normally close the passage through said return duct, and a weight controlled valve member in said duct means to permit excess air to be directed through an annular space between said cylindrical extension and said trusts-conical ring, said blower and electric motor being confined in said housing.

4. In a liquid fuel burner for outdoor dryer installations, as set forth in claim 3 in which said duct means for the major portion of its length is formed by an angular member secured in the corner of said housing between the front Wall and one of the side walls thereof.

5. In a liquid fuel burner for outdoor dryer installations, comprising a vertical housing having front, rear and side walls connected at their upper ends by arcuately curved walls, said front wall being provided with a round opening in the upper end thereof, an air motor casing mounted in back of said opening having a peripheral air inlet and a central discharge opening, a cylindrical shaft support attached to said casing, a rotary shaft extending through said support, anti-friction bearings in said support for rotata bly mounting said shaft, a vaned rotor wheel secured to said shaft, an atomizer cup secured to one end of said shaft and projecting through said open 7 ring, a cylindrical extension formed on said casing communicating with the discharge opening therein and arranged concentrically with respect to said cup, a frustoconical heat shield secured to said casing along the marginal edge of said opening, vane members in said cylindrical extension arranged at an angle extending in a direction "opposite to the direction of cup rotation, a liquid fuel p-ipe extending through said shaft having a spray nozzle provided on the end thereof having liquid fuel spray orifices, a rotary air blower mounted in the lower portion of said housing having inlet and outlet openings, an electric motor for driving said blower, a duct extending from the air outlet of said blower to the peripheral air inlet of said motor casing, an air return connected to said first named duct with its other end connected to the air inlet of said blower, a screened air inlet in said return duct, a gravity biased valve plate in said first duct to close the opening to said return duct, a weight cont-rolled valve plate in said first named duct to permit excess air to be discharged through the annular passageway between said cylindrical extension and said frusto-conical ring, and an adjustable valve plate in the upper end of said first named duct for restricting air References Qited by the Examiner UNITED STATES PATENTS 1,605,629 11/26 Warner "158-77 1,845,028 2/32 Macrae et a1. 15877 2,000,733 5/35 Avery 15815 2,214,246 9/40 Finnigan 158-76 2,986,327 5/6 1 Hunter 230 22 3,111,979 11/63 Peoples 158-76X FOREIGN PATENTS 31,032 8/26 France. 850,779 9/39 France.

20 FREDERICK L. MATTESON, in, Primary Examiner.

MEYER PERLIN, JAMES W. VJESTHAVER,

' Examiners. 

1. IN A LIQUID FUEL BURNER FOR OUTDOOR DRYER INSTALLATIONS, COMPRISING A VERTICAL HOUSING HAVING A FRONT WALL PROVIDED WITH AN OPENING IN THE UPPER PORTION THEREOF, AN AIR MOTOR CASING MOUNTED IN SAID HOUSING IN BACK OF SAID OPENING IN THE UPPER PORTION OF SAID VERTICAL HOUSING, SAID CASING PROVIDING A MOTOR CHAMBER, A CYLINDRICAL EXTENSION ON SAID MOTOR CASING COMMUNICATING WITH SAID CHAMBER FORMING AN AIR DISCHARGE PASSAGE THEREFROM, A MOTOR SHAFT ROTATABLY MOUNTED IN SAID CHAMBER IN SAID CASING, A ROTOR ON SAID SHAFT HAVING VANES ADAPTED TO BE DRIVE BY AIR ENTERING THE CASING THROUGH AN INLET OPENING THEREIN, A BURNER CUP ON SAID MOTOR SHAFT EXTENDING THROGH THE OPENING IN SAID FRONT WALL AND ARRANGED CONCENTRICALY WITH RESPECT TO SAID CYLINDER, A MOTOR DRIVEN BLOWER IN THE LOWER PORTION OF SAID HOUSING BENEATH SAID AIR MOTOR CASING HAVING AN INLET AND AN OUTLET, AN ELECTRIC MOTOR DRIVINGLY CONNECTED TO SAID BLOWER, DUCT MEANS COMMON TO AT LEAST ONE WALL OF SAID HOUSING CONNECTED TO SAID OUTLET AND TO THE AIR INTAKE IN SAID MOTOR CASING, AND A FRUSTO-CONICAL MEMBER SECURED TO SAID HOUSING ABOUT THE MARGINAL EDGE OF SAID OPENING THEREIN AND ARRANGED CONCENTRICALLY WITH RESPECT TO SAID CYLINDER AND BURNER CUP FOR DIRECTING AIR IN A CONVERGENT PATH TO THE BURNER CUP, SAID MOTOR DRIVEN BLOWER, AIR MOTOR CASING AND DUCT MEANS BEING COMPLETELY CONFINED IN SAID HOUSING. 